As a result of the energy crisis, considerable attention has been lately directed to the utilization of solar heat collectors. Predominantly the apparatus that is used is mounted on the roof of a dwelling or building and very little attention has been given to the utilization of heat exchangers installed on vertical building walls, and more particularly doors or other movable openings into a building.
In the prior art the principal attention that has been given to the utilization of solar heat collectors, particularly of the air exchange type, has been collectors that mount on roofs of buildings. Examples of this type of apparatus are seen in the Koizumi et al patent U.S. Pat. No. 4,108,155. In utilizing solar collectors in walls, the only prior art known is seen in U.S. Pat. Nos. 4,068,652 and 4,050,443, and in French Pat. No. 2,303,250. The prior art, however, is singularly lacking in a solar collector heat exchanger which is adapted to be used in movable openings through the walls of a building.